What was found
AIRCRAFT WAS GROUNDED: WHILE TAXIING, WE NOTICED THAT THE AC WAS UNUSUALLY DIFFICULT TO TURN AND MANEUVER. IT REQUIRED SIGNIFICANTLY MORE ENGINE POWERTHAN NORMAL TO TAXI, AND ALSO HAD TO APPLY MORE BRAKE PRESSURETHAN USUAL.DESPITE NOT USING EXCESSIVE BRAKING, BRAKE TEMP NUMBER 2 UNEXPECTEDLY INCREASED TO 340 DEGREES. DUE TO THE ABNORMAL TAXI CHARACTERISTICS AND ELEVATED BRAKE TEMP WE DECIDED TO RETURN TO THE GATE FOR FURTHER INSPECTION. MAINTENANCE REMOVED AND REPLACED #2 BRAKE ASSY IAW AMM 32-42-27.